The monitoring of environmental conditions in computer systems and especially peripheral devices for such systems is of utmost importance. The sooner a problem or potential problem is detected, the better. Moreover, a rapid response to a potential problem and especially to an existing problem is critical. Systems in the past employed heat exhaustion fans and warning lights to signify a problem. Also, warning sirens or horns were used to notify an operator of a problem. However, time is crucial in correcting a problem. Better yet, if a problem could be anticipated and corrected before it became a crisis then so much the better.
However, a downside risk associated with adding circuitry for environmental monitoring is that the Mean Time Between Failure ("MTBF") for the peripheral device cabinet is compromised due to the increased chances of a single point failure occurring somewhere within the system. On the other hand if a backup parallel system could be added that would take over control in the event of a failure, the MTBF would again approach the same value as if no monitoring circuitry were present.